UK Tax Advisor/service (Muscat)

Does anyone know or have a good UK Tax advisor who understands and knows the tax implications for expats. Also who can file taxes on our behalf? As per my understanding we can no longer submit the self-assessments online as we no longer live in the UK. And need to file the paper version by the 31st of October for the Protected content tax year. We have registered for the nonresident landlord program etc… so just need to get the filing of taxes right for UK income. Thanks